Apparatus for X-ray analysis of liquid materials



May 7, 1957 DYROFF 2,791,698

APPQRATUS FOR X-RAY ANALYSIS OF LIQUID MATERIALS Original Filed March28, 1955 I Sheets-Sheet 1 FIG.I

COOLED SPECIMEN HOLDER METAL 5 HOLDER RECEIVING SOCKET GE'GER COUNTERWINDOW) ASING ROTATION l2 3 \\1\ l COLLIMATORS 4 \q R 4 X-RAY TUBE 14;

' SINGLE CRYSTAL ANALYSER j gg I i ON IOMETER FIG. 4.

George V. Dyroff Poul Skibo, Jr. Inventors August Y. Mottlou' 2,791,698APPARATUS FOR X-RAY ANALYSIS OF LIQUID MATERIALS Original Filed March28, 1955 I May 7, 1957 G. v. DYROFF ETAL 2 Sheets-Sheet, 2

I lnver ators Aflqrney George V. Dyroff Puul' Skibu, Jr. August Y.Motfluu W APPARATUS FOR X-RAY ANALYSIS OF LIQUID MATERIALS Continuationof abandoned application Serial No. 497,194, March 23, 1955. Thisapplication December 19, 1956, Serial No. 629,420

7 Claims. (Cl. 250-435) The present invention relates to apparatus forX-ray analysis of liquid materials for the spectographic determinationof the components thereof. More particularly, this invention isconcerned with such apparatus in its employment of X-ray analysis forthe spectographi'c determination of the presence of metals and metalliccompounds in liquids, and especially liquid hydrocarbons such as may beemployed as feed stocks for catalytic cracking systems. This inventionrelates more specifically to a device for holding a liquid sample in thepath of a stream of X-rays, wherein the device automatically presents apredetermined thickness of sample to the action of the X-rays, whilesimultaneously affording a means for enhancing the effect of said X-rayson the sample.

States Patent sis is not excessively protracted.

Analysis by the X-ray fluorescence technique has been termination of theextent to which a solid material, such The invention is set forth hereinas a continuation of our co-pending application Serial No. 497,174,filed March 28, 1955, now abandoned.

In the catalytic cracking of hydrocarbon oils, it is wel known that theactivity of the catalyst employed is adversely aflected by the presenceof certain metals or metallic compounds in the materials brought intocontact with the catalyst during progress of the catalytic reaction. Bythe deposition of-even minute quantities of such metals and compounds onthe catalyst particles, the catalyst is contaminated. Such contaminationis indicated by, and results in, an undesirable increased production ofhydrogen with a corresponding reduction in efiicient operation of thesystem for the recovery of gasoline and other desired hydrocarbonmaterials. Such contamination may result in an increase in hydrogenproduction from a normal production in the range of from about one toabout ten volume percent, to a production in the range of from about tento about thirty volume percent. The light ends handling facilities ofand the interference of the system may thus become overloaded beyondtheir design capacity, necessitating cut-backs in the initial feed ofcracking stock, and resulting in a reduced production of useful andvaluable products.

The detrimental effect of catalyst contamination by certain metals andtheir compounds has been recognized for some time. Many procedures havebeen suggested for the removal of such metals from feed stocks assupplied to a catalytic reactor, as well as for removing contaminantsafter they have been deposited on the catalyst materials. Suchprocedures would require considerable investments for additionalequipment for processing feed stocks in addition to increasingmaintenance and operating costs. Such procedures, also, in the absenceof means to determine the contaminant content of feed stocks, wouldrequire total treatment systems wherein the entire feed to a catalyticreactor must be treated continuously in order to avoid contamination byany particular portion thereof.

Eflorts have been made to avoid the necessity for .total treatmentsystems as by intermittent analysis of feed stocks. Most analysis tionof feed characteristics quickly enough to permit ac-.

complishment of corrective action within minutes rather than hours ordays. Such a method and apparatus most desirably should provide fordirect sampling, and immediate analysis of the feed stock at regularintervals, but alternatively samples may be withdrawn and removed tolaboratory facilities foranalysis, provided the time interval betweensample withdrawal and completed analy found to offer attractivepotentialities, and several types of equipment have been developed forthis purpose. Suchtechniques have been employed successfully for thedeas a powdered cracking catalyst has been contaminated by metals suchas iron, nickel, and vanadium, and their compounds. It is obvious,however, that while the results of such determination may be useful toindicate the need for catalyst replacement, it would be more desirableto determine the existence of such contaminants in the materials whichare to be brought into contact with the catalyst, and as a result ofsuch contact tend to produce degradation of the catalyst.

The application of X-ray fluorescence techniques to the inspection ofliquids has not been successful, however, for several reasons. To alarge extent, the lack'of success has been due to an inability ofexisting equipment to provide for reproducible sample volumes anddepths,- background fluorescence created by the sample holder. It is anobject of the present invention to overcome these defects in suchequipment, primarily by improving the geometry of the related ap'-paratus elements, and by providing improvedsample holding means. Itis'also an object of this invention to pro vide a sample holder whichincludes a means for reduc ing background interference and for enhancingor intensifying thepeak height of fluorescent radiation of the metalliccomponents of the sample under influence, of X-ray radiation of thesample. It is a further object of the invention to provide a sampleholder wherein the contained sample may be maintained at a constanttemperature, and additionally may be adapted to direct sampling andprocess control procedures. A still fur-- ther object is to provide anX-ray analysis system suitablefor employment as a means for controllingthecontent of metals and metal compounds in'the feed as sup-v plied to atreating or reaction process. 1 j The invention and its objects may bemore clearly understood from the following description, when it is readin conjunction with the following drawings, in which: Y

Fig. 1 is a schematic illustration of an X-ray fluorescence analyzerapparatus, showing the geometry of related elements according to thisinvention;

Fig. 2 is an enlarged and more detailed illustration of the sampleholder of Fig. l, partly in vertical section;

Fig. 3 is a view in vertical section of another form of sample holderaccording to this invention; and

Fig. 4 is a schematic showing of the application of an analyzeraccording to Fig. 1, employing a sample holder according to Fig. 3, to asystem for controlling the metal content of the feed stream to acatalytic crack ing reactor. 4

Referring to the drawings in greater detail, wherein I Patertted'May 7,1 957..

methods, however, have re-. quired an extended series of stepswhich'involve hourslike parts are designated by the same numerals, inFig. 1, the numeral 1 designates a housing unit. Included as partsthereof are a sample holder socket or thimble 2 supported on the upperwall of the housing 1 and extended downwardly therethrough, and aflanged tubular housing extension shield 3 opening from. a sidewall port4 in the housing to extend angularly downward therefrom. In thestructure as shown, the thimble 2 and the shield 3 are disposed so thatlongitudinal axis of the shield and the vertical axis of the thimble liein the same vertical plane, with the longitudinal axis of the shieldinclined downwardly from a horizontal plane common to the lower end ofthe thimble 2 and along a line which intersects the thimble axis in thatplane as shown. The thimble 2 is adapted to receive a sample holder,designated by the numeral 5 in Fig. 1 and illustrated in greater detailin Fig. 2. Also as shown, the sample holder 5 is supported in andconcentric with the thimble 2 by means of an annular radial shoulder 6,formed in the outer surface of the holder, which bears upon the upperand outer end of the thimble 2. The lower or inner end of the sampleholder '5 terminates in substantially coplanar relation to the inner endof the thimble 2.

An X -ray tube 7 is extended horizontally into the housing 1 insubstantially right angular relation to the plane which is common to thelongitudinal and vertical axes'of the shield 3 and thimble 2respectively, with the tube below and offset from the thimble in adirection diametrically opposite to the shield 3. According toconventional construction, the tube 7 is provided with a target element8, and an aligned X-ray discharge window 9. In the structurecontemplated, the tube 7 is disposed so that the target 8 issubstantially centered on and in right angular relation to a radius ofthe tube which lies in the aforementioned plane common to the verticaland longitudinal axes of the thimble 2 and shield 3 respectively, andwhich also is substantially aligned with the center of the thimble 2and; in right angular relation to the longitudinal axis of the shield 3.Preferably the target element 8 is formed of high grade tungsten, whichcontains a minimurn'amount of impurities in the form of iron, nickel,vanadium, or other substance likely to be included or contained inthesubstance to be analyzed, and to be determined by such analysis. Thewindow 9 is preferably of beryllium, but may be mica, or Lindeman glass.

' Associated with the apparatus thus far described, is a goniometerplate 11 of which the inner face, presented in Fig. l, liessubstantially in a plane parallel to that which is common to thelongitudinal and vertical axis of the shield 3 and thimble 2respectively. The plate 11 is disposed for rotation on a horizontal axiswhich intersects the axis of shield 3 at right angles thereto, and is atright angles to the aforementioned planes. The plate 11 is disposed forrotation about its axis by any suitable means, not shown, through an arcof at least 165, from a zero point which is below a horizontal planethrough the plate axis, as well as that which is" common to the lower orinner end of the thimble 2 and/ or sample holder 5, and which is in avertical plane common to that through the axes of the shield 3, and ofthe thimble 2. In a preferred form, this zero point is 30 below thehorizontal planes mentioned. Mounted on the goniometer plate 11, is abracket 12 adapted to support a collimator 13, and a Geiger counter 14.The collimator 13 is a hollow cylindrical shell, in which may bedisposed a bundle of elongated tubular elements coextensive with theshell and parallel to the axis thereof. Both. the collimator and theGeiger counter are aligned coaxially and sighted" so that their comomnaxis is parallel to a radius of the goniometer plate 11, and liessubstantially in the same vertical plane as that which is common to thelongitudinal axis of the shield 3 and the vertical axis of the thimble 2and/ or holder 5. Y

A bracket 21 is mounted for rotation about the axis of the plate 11also. This bracket 21 is adapted to support a. difiraction crystal 22with the upper surface of. the crystal in a plane common to that of theplate axis, and in a position such that the vertical plane common to thelongitudinal axis of the shield 3 and to the vertical axis of thethimble 2 and/ or holder 5 passes through the surface of the crystal insubstantially right angular relation thereto. The bracket 21 is arrangedfor rotation in unison with the plate 11, and preferably by the samemeans, but at a rate which is one half that of the plate 11 and bracket12. Initially, the bracket 21, with crystal 22, the collimator 13 andGeiger counter 14 on bracket 12 are aligned in such fashion that theaxis of the collimator 13 and Geiger counter 14 as well as the surfaceof the crystal are common to a line extensible through the axis of theplate 11 and the center of the thimble 2 and/or holder 5 at the lower orinner ends thereof.

Substantially coextensive with the shield 3, is a second collimator 31.This collimator is similar to the collimator 13 previously mentioned,but whereas the shell of collimator 13 may contain a bundle of tubularelements, the collimator 31 preferably contains one or more transversediscs each defining a diametric slot, and where a plurality of suchdiscs are employed, wherein the slots are in a parallel and longitudinalalignment. In the drawing described, both discs and tubular elementshave been omitted for simplification, as both forms of collimator arewell known in the art. The collimator 31 is ad justably supported in theshield 3 for substantially coaxial alignment therewith.

in Fig. 2 is shown the structure of the sample holder designated in Fig.l by the numeral 5. In the view of Fig. 2, the numeral 51 indicates thetubular outer wall of the device, while the numeral 52 indicates atubular inner wall of lesser diameter disposed concentrically of 51 toprovide an annular space between them. At their upper ends, the wallmembers 51 and 52 are connected by means of an annular ring 53,press-fitted between them and then welded to form a fluid tight seal. Attheir lower ends, the inner wall member 52 is extended beyond the outer'wall member 51, the space between wall members being closed by a ring54 at the level of the lower end of the wall member 51 and disposed inthe manner of ring 53. The space between wall members 51 and 52 is thusclosed to form an annular chamber. The chamber as shown is divided intosections by means of vertical baflles such as baffles 55 and 56. Aninlet conduit such as indicated by the numeral 57 provides for theintroduction of a heat exchange fluid into the chamber on one sideof'the bathed chamber, while an outlet conduit such as indicated by thenumeral 58 provides for withdrawal of the heat exchange fluid from theother side of the chamber,

The lower end of the sample holder is suitably provided with a closurefor the lower end of the inner tubular wall member 52-. As shown, theextended portion of the wall member 52 is extcriorly threaded to receivea first ring 59, machined to provide a shouldered enlargement of themember 52, which is adapted to receive a second ring 60 in press fittedrelation. The ring 60 is provided with an annular flange 61 extendingradially inward, and having an inner diameter equal to that of the wallmember 52. When assembled the flange 61 substantially engages the end ofthe ring 59 and the end of the wall member 52 A diaphragm closure forthe assembly is indicated by the numeral 62. As shown the closure is athin sheet of a plastic material stretched over the end of the member 52and ring 59 to be held in fluid tight relation thereto by means of thering 60. Although a mica disc, Lindeman glass, or even a thin metal discof a metal such as beryllium may be used as the closure means, it ispreferred that the closure be formed from a material such as Mylar,which is a high molecular weight polyester material produced fromethylene glycol and terephthalic acid by condensation,

senses the compound being known as polyethylene terephthalate.Thismaterial has the characteristic of extremely low absorption forX-rays and any secondary radiations produced thereby. It also has a hightensile strength even in thin films of a thickness as low as about mill.Due to its extreme lack of absorption for X-ray, however, this materialmay be used in any thickness required for the service intended. With theclosure applied, a sample chamber 53 is formed within the wall member52.

Also included as functional parts of the sample holder are a plungerdisc 71, plunger rod 72 and closure plate 73. The plunger disc 71 is ofa diametersubstantially equal to the internal diameter of the tubularwall mem her 52, in which it is adapted to fit in longitudinallyslideable, transverse relation. It is of a thickness adequate to providerigidity and permit suitable machining of the lower face and edgeportions, and also to provide for threaded engagement with plunger rod72 at the lower or inner end thereof.

The rod 72 is of a length somewhat greater than the distance from theclosure 62 to the upper end of the device. The upper or outer end of theplunger rod 72 extends through a central passage in the plate closureelement 73 and a central raised boss 74 on the upper or outer surfacethereof, the rod 72 being reciprocally moveable through said passage.Means such as set screws 75 are provided in the boss to hold the rod inany desired fixed relation to the plate or boss, and consequently tohold the disc 71 in any desired relationship to the closure disc 62.Suitably spaced indicia lines 76 are shown which encircle the upper endof the rod 72, providing gauge markings whereby the space relation ofthe lower surface of the disc 71 to the upper surface of the closure 62may be accurately determined. The disc 71 as shown is furthercharacterized by a series of passageways 77 extended vertically throughthe thickness of the disc and opening through both upper and lowersurfaces. Alternately, or in addition to such passageways 77, the edgeof the disc may be provided with a plurality of vertical grooves orslots 78 disposed in circumferentially spaced relation, peripherally ofthe disc.

In operation of the apparatus as represented by Fig. 1, and using asample holder such as illustrated by Fig. 2, a liquid material is firstintroduced into the chamber 63. The sample holder is then inserted inthe thimble 2. The outer end of the plunger rod is inserted through thecentral passage in the cover plate 73 and boss 74, and as previouslydetermined, is positioned in fixed relation therein, by means of setscrews 75 so as to provide a certain clearance between the under surfaceof the disc 71 and the upper surface of the diaphragm closure 62.Normally, this clearance will not be more than inch, and preferablyabout A; inch, but this clearance depends to some extent on theviscosity and density of the liquid as well as upon the estimatedcontent of the material to be discovered by analysis. dis'c set in thecover plate for the desired clearance, the assembly is inserted in thechamber and permitted to sink through the liquid sample until the coverplate comes to rest on the upper end of the sample holder. The excess ofsample liquid flows through the passages 77 and 78 as the plunger sinks.An excess of the sample is desirable in order to facilitate maintenanceof substantially a constant temperature in the material exposed belowthe plunger disc 71. Although other means may be employed, in the sampleholder as shown, a heat exchange fluid such as water is circulatedthrough the annular space between the members 51 and 52'by way of theconduit connections 57 and 58 into indirect heat exchange relation withthe excess of sample above the disc 71 and also by contact between thedisc and wall member 52. In turn the exposed sample portion below thedisc 71 is in heat exchange relation to the disc and to a slight extent,byconvection, with the body of excess sample above the disc. The purposeof 'suchheat'ex change relationship is primarily to maintain a substan-With the plunger rod and r tially constant density of the exposed samplebelow the disc, with a minimum eifect thereon by' temperature changes.Such temperature changes may be occasioned not only by variations ofambient temperature but also and primarily as a result of X-rayirradiation of the exposed sample. Q

With the sample and holder in place, the exposed portion of the sampleis subjected to X-ray irradiation from the tube 7, substantially asindicated by broken arrows in Fig. 1. It is well known that when soirradiated, the various component elements of the sample materialfluoresce in characteristic fashion, each element emitting secondaryrays, identified as K-rays. .For each component or contained element theK-rays emitted are known to have a substantially specific wave length.This char.- acteristic is especially identifiable with metals and theircompounds. For example, iron, nickel and vanadium exhibit characteristicK-ray wave lengths of about 1.94, 1.66 and 2.50 A. units respectivelywhen irradiated with X-rays, using a tungsten target at 35 kv. and 20ma. for iron and nickel and 50 kv. and 50 ma. for vanadium. Anadditional characteristic ofeach component, when so irradiated, is thateach distinctive wave length attains a maximum measurable intensity orpeak when difiracted and reflected by a crystal, such as a lithiur'nfluoride crystal, interposed in the ray path at a specific anglesubstantially according to the Bragg formula Thus, for iron the peakintensity is obtained with the crystal at a Bragg angle of 57.25 (20);for nickel at a Bragg angle of 48.5 (20); and for vanadium at Braggangle of 76.6 (20). In the apparatus as shown, the bracket 21 andcrystal 22 may be rotated so as to present the crystal surface to therays issuing from the fixed collimator 31 at any desired angle. Thecollimator 31 serves to render the rays parallel, and to direct themtoward the axis of the bracket, and thereby the surface of the crystal.

In order to measure the intensity of the rays reflected from the crystalit is essential that the measuring means, such as the Geiger counter,indicated in Fig. 1 by the numeral 14, be sighted on the crystal at anangle substantially equal to the angle of incidence of such rays This isaccomplished by the goniometer arrangement previously indicated, whereinthe measuring means is rotated at twice the rate of the crystal in asystem'in which the fluorescent rays are collimated and directeddownwardly at an angle below the horizontal and in whichthe geometricrelationships of the sample holder, collimatorand the goniometer plateand measurement means, are such as to establish a zeroed alignment ofthese parts at that angle.

The rays diffracted and reflected by the crystal. 22 are also renderedparallel, as by the collimator13, and'then pass into the measuringdevice, such as the ionization chamber provided by a Geiger counter,indicated in Fig. 1 by the numeral 14. The current produced byionization of the gas contained in the chamber'indicates quantitativelythe intensity of the radiations received, and may be measured directlyby means such as an electroscope or electrometer, or the current may beamplified for measurernent in other ways. The amplified current may alsobe employed in connection with suitable relays and auxiliary circuits toactivate suitable measuring recording and control instruments forpurposes such as later described with reference to Fig. 3 and especiallyFig. 4. I

The sample holder as contemplated by the present invention additionallyutilizes a further phenomenon or characteristic of X-ray irradiation ofmetals. It is known that the fluorescence of irradiated-metalsmay beintensified or enhanced by exposure to the K-rays of other metals havinga higher atomic number. Thus, in thei'sample holder as represented inFig. 1 and-as more particularly described with reference to Fig. 2, thedisc71 is formed of, or faced with a metal of higher atomic number thanthe subject metal for which th sample contained by holder '5 is to beanalyzed. For example, in analyzing for iron, nickel'on vanadium in thesample the exposed lower surface of the disc, 71 might be either cobaltor copper for iron analysis, copper or zinc for nickel analysis, andchromium or manganese for vanadium analysis. Of these, it is preferredthat copper, zinc and chromium be employed in analysis for iron, nickeland zinc respectively. In addition to enhancing the intensity of K-rayemission by the subject metals, the use of a backing disc of the natureand in the manner described advantageously reduces backgroundinterference, and initial radiation effectivenes's. X'-rays which mightotherwise pass through the sample'without eifective contact with thesubject elements in the sample, or be scattered at the upper sampleinterface, are made to contact a metal which in turn emits K-rays havingthe. capacity to produce fluorescence of a subject element which ischaracteristic of an original Xraycontact. Thus a greater incidence ofcontact fluorescence is obtained. Background radiation, so called, isalso reduc ed lay avoiding the scattering effect produced when: X-rayspass through an interface such as between a liquid. surface and agaseous atmosphere: above it.

Referring now to Fig. 3, the numeral 101 designates a compartmented:container which includes an outer chamher. or compartment 102. Thechamber 102 is closed at the upper end by means of a removable coverplate 103, and has a bottom wall 104. As shown, the wall 104 has anannular form and is provided with an upstanding rim 105 along its innerperipheral edge. The rim 105 in turn has an annular flange portion 106extended radially inward therefrom, and a portion 107 which extendsoutwardly through the bottom wall.

The inner wall of the rim 105, including the extended portion 107 isthreaded to receive a closure 108 for the inner end of the upstandingrim, forming therewith an inner chamber or compartment partly within thecompartment 102, and opening outwardly through the bottom wall 104. Theclosure 108 as shown has a center portion 110 and an upstanding rimportion 111 of a diameter less than the rim 105, defining an annularspace 112 between them. The rim portion 111 is flanged annularly outwardas indicated by the numeral 113, the flange being peripherally threadedto engage the threaded inner wall of the rim 105. The numeral 114designated an annular gasket engaged between the flanges 106 and 113.

The outer end of the rim 105 is also provided with a closure. As shown,this closure includes an inwardly flanged slip ring 115, wherein theannular flange portion is designated by the numeral 116, and a diaphragmmemher 117 which is held in place by engagement between the slip ring115 and the extended wall 107 of the rim 105. The diaphragm 117 ispreferably of a material which is substantially non-absorbent forX-rays, such as the material indicated by the numeral 62 in Fig. 2,which is a high molecular weight polyester material produced fromethylene glycol and terephthalic acid by condensation. Alternatelyas inthe structure of Fig. 2, a thin disc of mica, Lindeman glass or a metalsuch as beryllium may be employed. In the latter instance, it ispreferred that the outer wall of the rim portion 107 be threadedexteriorly to receive an interiorly threaded closure ring in place ofthe slip ring 115.

The closure 108 is further characterized by having a total thicknesswhich is less than the length of the rim 105 from the flange 106 to theouter end of the extended portion 107. Thus the under or reverse surfaceof the closure 108 is disposed in spaced relation to the upper orobverse surface of the diaphragm 117 or any disc element which may besubstituted therefor, and together vertically define a sample receivingchamber 118, communicating peripherally with the annular space 112.Preferably, the relationship between the opposed surfaces of the closureelcments 108 and 117 is similar to thatas set forth between the undersurface of the disc 71 of Fig. 2 and the diaphragm closure 62 thereof.Also, as set forth with reference to the disc 71 of Fig. 2 the closureelement 108 is formed of, or faced with a metal of higher atomic numberthan the metal for which a sample fluid contained in the chamber 118 isto be analyzed.

In the apparatus illustrated in Fig. 3 the number 121 designates aninlet conduit for the introduction of a fluid sample into. the samplechamber 118. The conduit 121 is extended through the compartment 102 soas to form a coil therein, and the innermost end of the conduit isconnected in fluid communication with the annular space 112, by way of apassageway 122 through the rim portion 111, and thence with the chamber118. An outlet conduit 123 also communicates with the annular space 112by way of the passageway 124 in the rim portion 111, and is extendedoutward therefrom through the container wall. A branch conduit 125connects with inlet conduit 121 exteriorly of the container 101 asshown.

Each of the conduits 121, 123 and 125 is provided with a valve meanssuch as the valves. designated by numerals 126, 127 and 128respectively. Preferably, these valves are provided for automaticoperation, and may be motorized or, as shown, may be solenoid actuated.In the Fig. 3, the numerals 129, 130 and 131 indicate solenoid typevalve operating mechanisms electrically connected to a current sourcethrough a relay circuit, diagrammatically indicated in the drawing anddesignated by the numeral 132. In the conduit system as shown, the relaycircuit in conjunction with an associated timer mechanism 133 isdesigned to actuate solenoids 129, 130, and 131 and thereby the valves126, 127 and 128 in a repetitive time sequence as follows, and startingwith all valves closed:

(a) Open valves 127 and 128 (-11) Close valve 128 and open valve 126 (c)Close valves 126 and 127 It is further contemplated that the containervessel 101 will be mounted in a suitable housing substantially in themanner of the sample holder 5 of Fig. 1. Such a mounting apparatus wouldalso include the equivalents of the X-ray tube 7 of Fig. I focused onthe closure disc or diaphragm 117, a goniometer plate, collimators,diffraction crystal and measuring means all in substantially thestructural and operating relationships as shown in Fig. 1 and describedwith reference thereto. The inlet and outlet conduits designated in Fig.3 by the numerals 134 and 135 respectively correspond to the conduitconnections 57 and 28 respectively, and provide for the circulation ofheat exchange liquid through the container vessel 101 in indirect heatexchange relation to the fluid in the conduit 121 and the chamber 118 ofthe apparatus as shown in Fig. 3.

In the employment of the device as illustrated by Fig. 3, the conduit121 is connected by a suitable source of a material to be analyzed. Thismight be a process flow line, or a storage reservoir or any othersuitable source. The timer mechanism 133 is then adjusted to a timeinterval adequate to permit the chamber 118 to be filled, purged, andrefilled from the sample source, while retaining the sample in thechamber 118 for the length of time required to obtain an optimumirradiation thereof, and to permit measurement of the diffractedsecondary K-rays. The conduit 125 in this system may occasionally beomitted and some of the advantages of the invention retained, butpreferably it is provided for connection to a source of a metal freepurging fluid, preferably miscible with the sample fluid and a diluenttherefor. For example, when sampling a gas oil, a water white keroseneor even gasoline might be employed as the purging material.

With the time sequence properly established, a sample material isadmitted to the chamber 118 by opening valves 126 and 127. Preferably,the sample material is permitted to flow through the chamber for a briefinterval,- and then -the valves 126 tially simultaneously, or in thesequence of valve -127 and then valve 126. The sample is then subjectedto X-ray radiation and analysis substantially in the manner describedwith reference to the operation of the apparatus as shown in Figs. 1 and2. When the allotted time for this analysis has expired, the valves127and 128 are opened and the sample chamber purged. The cycle may then berepeated by closing valve 128 and opening valve 126. -Where a separatepurge fluid is not employed, purging may be accomplished by the samplematerial itself, the operation of valves 126 and 127 being timed topermit aperiod of sample material flow through the chamber 118 betweensuccessive analyses. Also, the time cycle may be arranged so as toprovide any desired interval between analysis stages in the sequence ofoperation.

The apparatus as described with reference to Fig. 3, may be-employedmost suitably in conjunction with a process operation wherein it isdesirable that the metal content of a process'fiow stream be determinedin the field, and at more or less frequent intervals. The apparatus asshown in Fig. 3 is particularly adapted to be connected into acommercial scale system substantially as indicated by the showing ofFig. 4. As diagrammatically illustrated the process system includes avacuum pipe still 200 and separtaor 201 operated to produce a feed stockgas oil for catalyst conversion in a catalytic cracking reactor 202. Byclose control of temperature and pressure in the vacuum still andseparator, a feed stock gas oil may be produced in which the threeprincipal catalyst contaminating metals are present in amounts notsubstantially greater than 0.5 part per million for nickel, 2.5 partsper million for vanadium, and 3.0 parts per million for iron. The pipestill is connected to the reactor by a process flow line or conduit203,Inthis system, as shown, the numeral 204 designates a sample draw offline connected to an X ray analyzer unit 206 such as described withreference to Fig. 1, and which includes a sample holder of the characterdescribed with reference to Fig. 3. A conduit 207 provides for dischargeof the sampled material after analysis. Valves 208 and 209 in theconduits 204 and 207 control flow into and from the analyzer apparatus.Although not shown in this representation of the apparatus, the valves208 and 209 are preferably of the type described with reference to Fig.3, and including means for automatic operation. It is also contemplatedthat the apparatus assembly may include accessory equipment, of acharacter well known in the art, adapted to provide for motorized,reciprocal, and intermittent rotation of the goniometer plate accordingto a predetermined, timed sequence. Further, it is contemplated that bythe use of suitable and well known electrical sensing devices,amplifiers and relays, the signals produced by measuring means such asthe Geiger counter shown in Fig. 1 may be employed automatically toactuate controls for process apparatus, such as the pipe still of Fig.4, in order to maintain any desired metal content in the process flowstream therefrom.

What is claimed is:

1. In an apparatus for X-ray analysis of a liquid material forspectrographic determination of metallic components of said material,wherein a sample portion of said material is subjected to X-rayradiation to produce characteristic K-ray emission by each said metalliccomponent of said material, a holder for such sample portion whichcomprises a compartmented container including an outer compartment andan inner compartment, said compartments having upper and lower ends,closure means for the lower ends of said compartments, said closuremeans including a diaphragm substantially non-absorbent for X-rays,disposed in substantially fluid tight relation to said inner compartmentlower end, a metallic insert for said inner compartment, including meansto support said insert transversely of said inner compartment in closelyspaced parallel relation to said diaphragm, to oppose a and -127 areclosed substansubstantially continuous surface portion of said insert-tosaid diaphragm, and wherein at least said'surface portion is of a metalwhich reacts to X -ray radiation-by strong emission of secondary K-rays,means for the introduction,

of a sample portion of said liquid material into said inner compartmentand between said diaphragm and said metallic insert surface portion, andmeans for circulating a fluid heat exchange medium through said outercornpartment in indirect heat exchange relation to a liquid materialsample portion contained thereby.

2. In an apparatus for X-ray analysis of a liquid material for thespectrographic determination of metallic components of said material,wherein K-ray emission characteristic of each said metallic component ofsaid material is produced by X-ray radiation of a sample portion of saidmaterial, a holderfor such sample portion which comprises acompartmented'container including an outer compartment having a bottomclosure, and an inner compartment substantially concentric with saidbottom closure, said inner compartmenthaving a lower end extended andopening outwardly through said outer compartment bottom closure, aclosure for the lower endof said inner compartmentwhich includes adiaphragm substantially non-absorbent for X-rays, a metallic insert forsaid inner compartment, including means to support said inserttransversely of said inner compartment in closely spaced parallelrelation tosaid diaphragm, to oppose a substantially continuous surfaceportion of said insert tosaid diaphragm, and wherein at least saidsurface portion is of a metal which reacts to X-ray radiation by strongemission of secondary K- rays, means for the introduction of a sampleportion of said liquid material into said inner compartment and betweensaid diaphragm and said metallic insert surface portion, and means forcirculating a fluid heat exchange medium through said outer compartmentin indirect heat-exchange relation to a liquid material sample portioncontained thereby.

. 3. 'Anapparatus according to claim 2, wherein said continuous surfaceportion of said insert opposed to said diaphragm is of a metal selectedfrom the group which consists of cobalt, copper, zinc, chromium andmanganese.

4. In an apparatus for X-ray analysis of a liquid material for thespectrographic determination of metallic components of said material,wherein K-ray emission characteristic of each said metallic component ofsaid material is produced by X-ray radiation of a sample portion of saidmaterial, a holder for such sample portion which comprises a firstcylindrical wall portion, a second cylindrical wall portion of lesserdiameter and greater length than said first wall portion, each wallportion having top and bottom ends, said second wall portion disposedwithin said first wall portion in concentric, radially spaced relationthereto, the top ends of said wall portions being disposed insubstantially the same horizontal plane, and the bottom end of saidsecond wall portion being extended beyond that of said first wallportion, an annular spacer element at each end of said first wallportion secured to said first and second wall portions at their top andbottom end portions respectively and forming therewith an annularchamber, a fluid-tight cap for the bottom end of said second wallportion which includes an annular body portion and a diaphragm closurefor the bottom end of said second wall portion of a material which issubstantially non-absorbent for X-rays, said closure forming the bottomwall of said sample holder, a cover plate for the top end of said sampleholder, a plunger substantially contained within said second wallportion, including a plunger rod having inner and outer end portions ofwhich the latter is extended outwardly through said cover plate and isreciprocally moveable therein and a plunger disc secured to the innerend of said rod and having obverse and reverse surfaces of which thelatter faces toward said diaphragm closure and is of a metal whichreacts to X-ray radiation by strong emission of secondary K-rays, saiddisc adapted for a sliding fit in said second wall portion and at leastpartially defining a plurality of vertical passageways through saiddisc, said rod and cover also including means to limit movement of saidrod and for determining the spacing of said reverse disc surface fromsaid diaphragm closure, and inlet and outlet conduit means forcirculating a heat exchange fluid through said annular chamber.

5. In an apparatus for X-ray analysis of a liquid material for thespectrographic determination of metallic components of said material,wherein K-ray emission characteristic of each said metallic component ofsaid material is produced by X-ray radiation of a sample portion of saidmaterial, a holder for such sample portion which comprises acompartmented container vessel which includes an outer compartmenthaving a bottom wall and an inner compartment substantially containedconcentrically within said outer compartment and having a lower endopening downwardly through said outer compartment bottom wall and anupper end, a closure for the lower end of said inner compartment whichincludes a diaphragm substantially non-absorbent for X-rays, a metallicinsert disposed in the upper end of said inner compartment in closelyspaced relation to said diaphragm closure, said insert being of a metalwhich reacts to X-ray radia' tion by strong emission of secondaryK-rays, conduit means for circulating a heat exchange fluid through saidouter compartment, an inlet conduit for said liquid material sampleportion extended through said outer compartment into communication withsaid inner compartment and an outlet conduit therefrom, each of saidinlet and outlet conduits including valve means to interrupt flowthrough said inner compartment.

6. A sample portion holder according to claim 5 wherein said innercompartment is substantially defined by a hollow internally threaded,cylindrical walled member, wherein said upper end of said innercompartment is disposed within said outer compartment, and wherein saidmetallic insert comprises a peripherally threaded closure for the upperend of said inner compartment adapted for threaded engagement withinsaid cylindrical walled member and to provide a partition separatingsaid inner and outer compartments in indirect heat exchange relationshipthrough said insert.

7. In an apparatus for X-ray analysis of a liquid material forspectrographic determination of metallic components of said material,wherein a sample portion of said material is subjected to X-rayradiation to produce characteristic K-ray emission by each said metalliccomponent of said material, a holder for such sample portion whichcomprises in combination a compartmented container including an outercompartment and an inner compartment, said compartments having upper andlower ends, closure means for the lower ends of said compartments, saidclosure means including a diaphragm substantially non-absorbent forX-rays, disposed in substantially fluid tight relation to said innercompartment lower end, a metallic insert for said inner compartment,including means to support said insert transversely of said innercompartment in closely spaced parallel relation to said diaphragm, tooppose a substantially continuous surface portion of said insert to saiddiaphragm, and wherein at least said surface portion is of a metal whichreacts to X-ray radiation by strong emission of secondary K-rays, meansfor the introduction of a sample portion of said liquid material intosaid inner compartment and between said diaphragm and said metallicinsert surface portion, means for circulating a fluid heat exchangemedium through said outer compartment in indirect heat exchange relationto a liquid material sample portion contained thereby, a housingincluding a top wall and a tubular socket therein adapted to receivesaid sample holder to expose said closure means internally of'saidhousing, said housing further being; adapted to receive an X-ray tubeextended thereinto so as to direct X-rays angularly upward toward saidbottom closure diaphragm.

No references cited.

5. IN AN APPARATUS FOR X-RAY ANALYSIS OF A LIQUID MATERIAL FOR THESPECTROGRAPHIC DETERMINATION OF METALLIC COMPONENTS OF SAID MATERIAL,WHEREIN K-RAY EMISSION CHARACTERISTIC OF EACH SAID METALLIC COMPONENT OFSAID MATERIAL IS PRODUCED BY X-RAY RADIATION OF A SAMPLE PORTION OF SAIDMATERIAL, A HOLDER FOR SUCH SAMPLE PORTION WHICH COMPRISES ACOMPARTMENTED CONTAINER VESSEL WHICH INCLUDES AN OUTER COMPARTMENTHAVING A BOTTOM WALL AND AN INNER COMPARTMENT SUBSTANTIALLY CONTAINEDCONCENTRICALLY WITHIN SAID OUTER COMPARTMENT AND HAVING A LOWER ENDOPENING DOWNWARDLY THROUGH SAID OUTER COMPARTMENT BOTTOM WALL AND AUPPER END, A CLOSURE FOR THE LOWER END OF SAID INNER COMPARTMENTWHICHINCLUDES A DIAPHRAGM SUBSTANTIALLY NON-ABSORBENT FOR X-RAYS, AMETALLIC INSERT DISPOSED IN THE UPPER END OF SAID INNER COMPARTMENT INCLOSELY SPACED RELATION TO SAID DIAPHRAGM CLOSURE, SAID INERT BEING OF AMETAL WHICH REACTS TO X-RAY RADIATION BY STRONG EMISSION OF SECONDARYK-RAYS, CONDUIT MEANS FOR CIRCULATING A HEAT EXCHANGE FLUID THROUGH SAIDOUTER COMPARTMENT, AN INLET CONDUIT FOR SAID LIQUID MATERIAL SAMPLEPORTION EXTENDED THROUGH SAID OUTER COMPARTMENT INTO COMMUNICATION WITHSAID INNER COMPARTMENT AND AN OUTLET CONDUIT THEREFROM, EACH OF SAIDINLET AND OUTLET CONDUITS INCLUDING VALVE MEANS TO INTERRUPT FLOWTHROUGH SAID INNER COMPARTMENT.